The American Cancer Society reported late last month that the incidence of breast cancer rates among non-Hispanic white women in the U.S. did not continue to decline through 2007, after showing a significant decrease in the disease in 2002 and 2003, the first two years after The National Cancer Institute reported a dramatic drop in the number of women taking a form of estrogen therapy to treat the symptoms of menopause.
According to ACS, there are some explanations for the halt in declines of breast cancer rates after 2003, but none are definitive. One theory posits that the decrease in hormone replacement therapy use after 2003 may not have been large enough to continue delaying diagnoses. The other, more plausible hypotheses, involves the use of improved mammography technology after 2003 without the influence of hormone replacement therapy, which is known to increase breast density and compromise the diagnostic performance of mammograms and breast biopsies.
Between 2002-2003, breast cancer incidence rates among U.S. white women dropped by 7%. But, according to the NCI study, there was almost no change in the incidence rates among this group from 2003-2007.